Mother Nature produces some mind-boggling feats of navigation; swallows flying around the globe to Africa, salmon swimming upstream to spawn or wildebeest braving crocodiles as they migrate across rivers to reach the Serengeti plains.
However, nothing compares with the homing instinct of a tipsy reveller towards a late night kebab.
Picture the scene: our bon viveur swaying unsteadily as they reach the taxi rank. With a queue like an execution and over an hour to kill until the next bus, the only sensible option is to enter the sanctuary of the nearest kebab house.
Ensnared by the neon lights, like a moth to a flame, the helpless victim glimpses the beguiling slab of meat, twirling enticingly.
Before you know it, the warm meaty package is grasped tightly in their hands and the guilt-ridden sauce starts to dribble down their chin.
The vegetarian version doesn’t have quite the same allure, usually comprising some limp iceberg lettuce stuffed in a pitta with a squirt of sauce.
None the less, I’m optimistically heading to a recently opened vegan eatery that offers a 100 per cent plant-based menu but is named Karma Kebab.
This wee café has healthy green and grey painted walls, rough and ready wooden seating booths, and a relaxed student vibe.
The all important hi-tech kebab grill is on show, like a souped-up three bar electric heater. However in place of the regular dancing carne, there is a stubby slab of uninspiring vegan mock meat.
Customers place their order at the counter whether eating in or taking away. We are given a numbered wooden spoon to identify our grub before being left to wander to the back of the restaurant to take a pew.
Out front and centre there is a fridge filled with ethically responsible beverages. You will find no Coca-Cola here, only Karma Cola, beautifully designed cans of Gingerella, and Fairtrade Lemony Lemonade.
This joint is the culinary child of business partners Alan Collinson and Wade Tidbury, and offers a limited range of dishes including a choice of homemade sliced seitan or falafels, served on a toasted khobez or Middle Eastern flat bread.
There is also a version of the Quebec delicacy Poutine, or chips and gravy.
Seitan for the uninitiated, is made from wheat dough with the starch washed out. The remaining textured gluten is then seasoned and flavoured before being roasted or boiled. Never mind fake news, this really is fake meat.
The proprietors have a thing for wordplay to judge by the menu board, which has us chuckling.
Highlights are Good Karma, which features chilli sauce, salad and houmous, and Karma Sutra – the hot one with jalapeños laced with terrifyingly warm, Screaming Chimp chilli sauce.
The Karma Life (£7.50) seitan option, which I chose, is served with the addition of beansprouts and seeds, and I couldn’t resist a sneaky side order of chips (£2.50).
All the dishes arrive in dinky white enamel ashets. The kebab itself comes wrapped in aluminium foil, which makes tackling the dish a bit easier, however perhaps a regular old-fashioned plate might have made the task less arduous.
There is no civilised way I have discovered to demolish a doner; luckily I’m amongst friends. While the bread is crisp and the herby seitan, well, meat-like, the dish leaves me lukewarm.
I pair my dish with a Sencha green tea kombucha (£3.20), from Borders company Left Field. It is a low alcohol beverage made from a natural solution of tea, sugar and water.
Beloved by hipsters it is fermented with the help of bacteria and yeast. Breezy and refreshing is my judgment.
My partner in crime opts for the Karma Chameleon falafel meal deal (£10.00) this time and requests no chilli sauce.
Despite it being a quiet Monday lunchtime, with staff outnumbering customers, there’s a bit of a delay, and when it eventually arrives with the promised grilled peppers and olives it also includes the sauce.
Oh well, we let this slip and hungrily dive in. Overall not too shabby.
We also share a virtuous and healthy side salad (£5.00). Cucumber, peppers, olives and smoky, sun-dried tomatoes all feature, but to my taste buds the overwhelming flavour is of cabbage.
The verdict on our chips is that they are definitely not pale but sadly no great shakes, however the non-dairy mayonnaise is a surprisingly a winning accompaniment.
Perhaps the lesson of this modern morality restaurant tale is that anticipation is often better than the final result, and it is best to tackle the doner dish late at night following a glass or six.